GMO Coin Private API SDK for Forex and Cryptocurrency (Bun/TypeScript)

A modern, enterprise-grade Bun/TypeScript SDK for GMO Coin's Forex (FX) and Cryptocurrency trading APIs. Rebuilt for maximum type safety with TypeScript 5.9+, Zod validation, and the Result pattern.

Features

Core Capabilities

• Modern Toolchain - Optimized for Bun runtime and TypeScript 5.9+
• Type-Safe Result Pattern - Explicit error handling with { success: true, data: T } | { success: false, error: Error }
• SSOT (Single Source of Truth) - Unified Zod schemas for both validation and type inference
• REST & WebSocket APIs - Full coverage for FX and Crypto trading
• Strict Configuration - Complies with noUncheckedIndexedAccess and exactOptionalPropertyTypes

Production-Ready Features

• Rate Limiting - Automatic management (6 GET/s, 1 POST/s, 1 WS/s)
• Metrics & Audit - Prometheus metrics and masked PII audit logging
• Enterprise Ready - Built-in Fastify service with JWT auth and multi-tenancy

Requirements

• Bun: 1.2+ (Recommended)
• Node.js: 22+ (LTS)

Quick Installation

bun add gmo-coin-sdk

Quick Example (Result Pattern)

import { FxPrivateRestClient } from 'gmo-coin-sdk';

const fx = new FxPrivateRestClient(process.env.FX_API_KEY!, process.env.FX_API_SECRET!);

// Get account assets with Result pattern
const result = await fx.getAssets();

if (result.success) {
  console.log('Balance:', result.data);
} else {
  console.error('Operation failed:', result.error.message);
}

// Type safety is guaranteed within the success block

API Clients

REST Clients

| Client | API | Purpose | | ------------------------- | -------------- | ------------------------------------ | | FxPrivateRestClient | Forex Private | Trading, order management, positions | | CryptoPrivateRestClient | Crypto Private | Trading, order management, positions | | PublicRestClient | Public API | Market data, tickers, orderbook |

Development with Bun

# Install dependencies
bun install

# Build
bun run build

# Test
bun run test

# Run examples directly without building
bun examples/get-crypto-info.ts

License

MIT